1. Field of the Invention
The present invention relates to an optical recorder/player, and particularly to a data recording method for an optical recorder/player which can perform stable data recording by controlling a laser recording power of the optical recorder/player.
2. Description of the Related Art
Generally, an optical recording medium is classified into three types depending upon the possibility of a repeated recording: a read only memory (ROM) type, a write once read many (WORM) type, and a rewritable type.
As a repeatedly rewritable disc, there exists a rewritable compact disc (CD-RW) and a rewritable digital versatile disc (DVD-RAM).
An arrangement of the recording region of the CD-RW disc, as shown in FIG. 1, is divided into a power calibration area (PCA) 101, a program memory area (PMA) 102, a lead-in area 103, a program area 104, and a lead-out area 105.
The PCA 101 is a region for correcting the laser recording power for recording data on the disc, and the PMA 102 has leading address information of the track on which data is recorded in the program area 104.
The lead-in area 103 and the lead-out area 105 store information on both defect areas of the disc and data recording information stored in the program area 104. Actual data to be recorded on the disc is recorded in the program area 104.
When data is recorded on the disc, it is necessary to correct the laser recording power because of the recording sensitivity of a disc film, temperature, and a difference of the recording sensitivity caused by laser wavelength variations. In recording the data, the correction of the laser recording power is referred to as optimum power control (OPC). The performance of OPC is well known in the art, and a general OPC process will now be explained with reference to FIGS. 2 and 3.
FIG. 2 shows an example of a signal to be detected when reproducing the data recorded on the disc through the OPC process, and FIG. 3 shows a variation of the gamma and modulation according to the laser recording power in the OPC process.
Data is recorded on the PCA 101 of the disc for 15 absolute time in pregroove (ATIP), with the laser recording power being changed at an interval of 1 ATIP. After the data is recorded as described above, the recorded data is reproduced at each laser recording power, and the modulation m is obtained from a peak and a bottom of an RF waveform as shown in FIG. 2 (m=I11/Itop).
Also, the gamma is derived from the following equation (1) to calculate the variation of the gamma and the modulation depending upon the laser recording power as shown in FIG. 3.
Gamma=dm/dPwxc3x97Pw/mxe2x80x83xe2x80x83(1)
Meanwhile, a target power satisfying a target gamma value in FIG. 3 is obtained based on reading the target gamma recorded on the disc. Using a multiplication factor recorded on the disc, an optimum write power (Pwo) is obtained from the following equation 2.
Pwo=(multiplication factor)xc3x97Ptargetxe2x80x83xe2x80x83(2)
where, the target gamma and the multiplication factor are information previously recorded when the disc is manufactured.
As described above, the OPC of the optical recorder/player is executed on the PCA 101 of the disc only to determine the laser recording power suitable for recording the data.
When data is recorded in all the data recording regions using the laser recording power set from the result of the OPC performed on the PCA 101, a problem arises. The data recording characteristic of each data recording region on the disc may be different, and a problem arises in that the optimum laser recording power may not be set for recording data in each data recording region.
Therefore, an object of the invention is to provide a data recording method for an optical recorder/player which can perform a stable data recording by controlling a laser recording power of the optical recorder/player to be in an optimum state with respect to respective data recording regions when recording data on an optical disc.
In accordance with the present invention, the above object is accomplished by providing a data recording method for an optical recorder/player, the method comprising the steps of: a) receiving data and start address information for recording the received data; b) performing an optimum power control (OPC) in a data recording region of an optical recording medium corresponding to the start address; c) setting a laser recording power suitable for recording the received data in the data recording region corresponding to the start address based on the OPC; and d) recording the received data in the data recording region corresponding to the start address using the set laser recording power.